In manufacturing semiconductor devices, there is known a phenomenon that a disconnection defect is caused in a connection via in interconnects formed in a semiconductor device due to stress migration. To prevent such a defect, therefore, for example, a plurality of vias are arranged (increase in the number of vias or vias arrangement) in a portion for connection between an upper interconnect and a lower interconnect in a substrate, alternatively, a dummy via is disposed (dummy via insertion) in an interconnect. Stress migration is a phenomenon that bubbles, each called “vacancy”, generated in a metal interconnect migrate due to the gradient of a stress caused in the interconnect. These vacancies migrate to be concentrated into a via, so that a space called “void” is increased in size. The increased space causes a disconnection defect.